I made a wind station using the two following sensors that I bought on e-bay.

• Wind Sensor JL-FS2 Wind Direction Sensor (4-20mA, 0-5V) Signal Output
• Wind Speed Sensor Anemometer Three Cups Aluminium Alloyed pulse signal output

I think they are quite nice. They are fed with 12V DC and are giving a 5V output signal. Therefore I'm using a 5V Arduino Mini Pro for the sketch.

The following sketch is measuring the wind data once a second, storing it into an array and doing calculations to get the average wind speed, direction and gust for each minute, each other minute and each 10 minutes.

Before getting the average the wind is split into it's vector components. Cool isn't it?

I upload the average 10 minute wind data to Weather Underground. It looks very smooth.

Here is the sketch:

/**
 * WindMonitor
 * 

About the windspeed sensor, have a look here:
https://www.dfrobot.com/wiki/index.php/Wind_Speed_Sensor_Voltage_Type(0-5V)_SKU:SEN0170#Connection_Diagram

*/
#define MY_NODE_ID 17

#define SKETCH_NAME "Wind Station"
#define SKETCH_VERSION "1.1.1"
#define DWELL_TIME 1000  // this allows for radio to come back to power after a transmission, ideally 0

//#define MY_DEBUG // Enable debug Serial.prints to serial monitor and arrays are smaller

#if defined MY_DEBUG
#define MY_BAUD_RATE 115200 // Sets the serial baud rate for console and serial gateway

#define Sprintln(a) (Serial.println(a))
#define Sprint(a) (Serial.print(a))
const uint8_t num1mReadings = 2; // Use a low value to free memory for making debug possible
const uint8_t num2mReadings = 2; // Use a low value to free memory for making debug possible
const uint8_t num10mReadings = 2; // Use a low value to free memory for making debug possible
const uint8_t FORCE_TRANSMIT_CYCLE = 10; // Force sending value even if hasn't changed after N cycles
const uint16_t WAIT_TIME = 5000;
#else 
#define Sprintln(a)
#define Sprint(a)
const uint8_t num1mReadings = 60; //Defines number of reading to calculate average windspeed
const uint8_t num2mReadings = 2;
const uint8_t num10mReadings = 10;
const uint8_t FORCE_TRANSMIT_CYCLE = 10; // Force sending value even if hasn't changed after N cycles
const uint16_t WAIT_TIME = 1000;
#endif

// Enable and select radio type attached
#define MY_RADIO_NRF24
//#define MY_PARENT_NODE_ID 0
//#define MY_PARENT_NODE_IS_STATIC
#include <MySensors.h>

#define LED_PIN 8
#define ANEMOMETER_ANALOG_PIN 0
#define WIND_VANE_ANALOG_PIN 1

#define CHILD_ID_WIND 0
#define CHILD_ID_WIND2M 1
#define CHILD_ID_WIND10M 2
#define CHILD_ID_GUST_DIR 3 // Specifically for wind gust direction
#define CHILD_ID_GUST2M_DIR 4
#define CHILD_ID_GUST10M_DIR 5


#define FORCE_TRANSMIT_CYCLE 60 // Force sending value even if hasn't changed after N cycles
uint8_t cycleCountWindSpeed = FORCE_TRANSMIT_CYCLE;
uint8_t cycleCountWindGust = FORCE_TRANSMIT_CYCLE;
uint8_t cycleCountWindGustDir = FORCE_TRANSMIT_CYCLE;
uint8_t cycleCountWindDir = FORCE_TRANSMIT_CYCLE;
uint8_t cycleCountWindSpeed2m = FORCE_TRANSMIT_CYCLE;
uint8_t cycleCountWindGust2m = FORCE_TRANSMIT_CYCLE;
uint8_t cycleCountWindGustDir2m = FORCE_TRANSMIT_CYCLE;
uint8_t cycleCountWindDir2m = FORCE_TRANSMIT_CYCLE;
uint8_t cycleCountWindSpeed10m = FORCE_TRANSMIT_CYCLE;
uint8_t cycleCountWindGust10m = FORCE_TRANSMIT_CYCLE;
uint8_t cycleCountWindGustDir10m = FORCE_TRANSMIT_CYCLE;
uint8_t cycleCountWindDir10m = FORCE_TRANSMIT_CYCLE;

float last_wspeed;
float last_wgust;
uint16_t last_wdirection;
uint16_t last_wgustdirection;
float last_wspeed2m;
float last_wgust2m;
uint16_t last_wdirection2m;
uint16_t last_wgustdirection2m;
float last_wspeed10m;
float last_wgust10m;
uint16_t last_wdirection10m;
uint16_t last_wgustdirection10m;

float windSpeedReadings[num1mReadings]; // the readings from the analog input
float windSpeedReadings2m[num2mReadings]; // For 2 minute average wind speed
float windSpeedReadings10m[num10mReadings]; // For 10 minute average wind speed
float windDirReadings[num1mReadings]; // the readings from the analog input
float windDirReadings2m[num2mReadings]; // For 2 minute average wind dir
float windDirReadings10m[num10mReadings]; // For 10 minute average wind dir
float windGustReadings2m[num2mReadings]; // For 2 minute wind gust
float windGustDirReadings2m[num2mReadings]; // For 2 minute wind gust direction
float windGustReadings10m[num10mReadings]; // For 10 minute wind gust
float windGustDirReadings10m[num10mReadings]; // For 10 minute wind gust direction
boolean got2mins = false;
boolean got10mins = false;

float windSpeed = 0.0; // Wind speed in meters per second (m/s)
float windDir = 0; // Wind dir in degrees 0-360
uint8_t readIndex = 0; // the index of the current reading
uint8_t minute2Index = 0; // the index of the current reading
uint8_t minute10Index = 0; // the index of the current reading
uint16_t sensorValue = 0; //Variable stores the value direct from the analog pin
const uint8_t wsMin = 22; // Mininum reading
const uint16_t wsMax = 1023; // Maximum reading
const uint8_t wdMin = 3; // Mininum reading
const uint16_t wdMax = 941; // Maximum reading
const uint8_t windSpeedMax = 30; // Wind speed in meters/sec corresponding to maximum voltage


MyMessage msgWSpeed(CHILD_ID_WIND, V_WIND);
MyMessage msgWGust(CHILD_ID_WIND, V_GUST);
MyMessage msgWDirection(CHILD_ID_WIND, V_DIRECTION);
MyMessage msgWSpeed2m(CHILD_ID_WIND2M, V_WIND);
MyMessage msgWGust2m(CHILD_ID_WIND2M, V_GUST);
MyMessage msgWDirection2m(CHILD_ID_WIND2M, V_DIRECTION);
MyMessage msgWSpeed10m(CHILD_ID_WIND10M, V_WIND);
MyMessage msgWGust10m(CHILD_ID_WIND10M, V_GUST);
MyMessage msgWDirection10m(CHILD_ID_WIND10M, V_DIRECTION);
MyMessage msgWGustDir(CHILD_ID_GUST_DIR, V_DIRECTION);
MyMessage msgWGust2mDir(CHILD_ID_GUST2M_DIR, V_DIRECTION);
MyMessage msgWGust10mDir(CHILD_ID_GUST10M_DIR, V_DIRECTION);

void setup()  
{
  Sprint(SKETCH_NAME);
  Sprint(F(" version "));
  Sprint(SKETCH_VERSION);
  Sprint(F(" (using MY_NODE_ID: "));
  Sprint(MY_NODE_ID);
  Sprintln(F(") says hello!"));

  // Initialize arrays
  for (readIndex = 0; readIndex < num1mReadings; readIndex++) {
    windSpeedReadings[readIndex] = 0;
    windDirReadings[readIndex] = 0;
  }
  for (minute2Index = 0; minute2Index < num2mReadings; minute2Index++) {
    windSpeedReadings2m[minute2Index] = 0;
    windDirReadings2m[minute2Index] = 0;
    windGustReadings2m[minute2Index] = 0;
    windGustDirReadings2m[minute2Index] = 0;
  }
  for (minute10Index = 0; minute10Index < num10mReadings; minute10Index++) {
    windSpeedReadings10m[minute10Index] = 0;
    windDirReadings10m[minute10Index] = 0;
    windGustReadings10m[minute10Index] = 0;
    windGustDirReadings10m[minute10Index] = 0;
  }
}

void presentation()  {
  // Send the sketch version information to the gateway and Controller
  sendSketchInfo(SKETCH_NAME, SKETCH_VERSION);
  wait(DWELL_TIME);
  // Register all sensors to gateway (they will be created as child devices)
  present(CHILD_ID_WIND, S_WIND);
  wait(DWELL_TIME);
  present(CHILD_ID_WIND2M, S_WIND);
  wait(DWELL_TIME);
  present(CHILD_ID_WIND10M, S_WIND);
  wait(DWELL_TIME);
  present(CHILD_ID_GUST_DIR, S_WIND);
  wait(DWELL_TIME);
  present(CHILD_ID_GUST2M_DIR, S_WIND);
  wait(DWELL_TIME);
  present(CHILD_ID_GUST10M_DIR, S_WIND);
  wait(DWELL_TIME);
}

struct speedAndDir {    
 float uv;
 float Dv;
};

struct speedAndDir windvec(float speedArr[], float dirArr[], uint8_t size) {
  /*
   *
   *       Function to calculate the wind vector from time series of wind speed and direction.
   *       
   *       Parameters:
   *           - u: array of wind speeds [m s-1].
   *           - D: array of wind directions [degrees from North].
   *           
   *       Returning speedAndDir struct values:
   *           - uv: Vector wind speed [m s-1].
   *           - Dv: Vector wind direction [degrees from North].
   *
   */
  struct speedAndDir o;
  float ve = 0.0; // define east component of wind speed
  float vn = 0.0; // define north component of wind speed

  for (int i = 0; i < size; ++i) {
    ve += speedArr[i] * sin(dirArr[i] * PI / 180.0); // calculate sum east speed components
    vn += speedArr[i] * cos(dirArr[i] * PI / 180.0); // calculate sum north speed components
  }
  ve = - ve / size; // determine average east speed component
  vn = - vn / size; // determine average north speed component
  o.uv = sqrt(ve * ve + vn * vn); // calculate wind speed vector magnitude
  // Calculate wind speed vector direction
  float vdir = atan2(ve, vn);
  vdir = vdir * 180.0 / PI; // Convert radians to degrees
  if (vdir < 180) {
    o.Dv = vdir + 180.0;
  }
  else {
    if (vdir > 180.0) {
      o.Dv = vdir - 180;
    }
    else {
      o.Dv = vdir;
    }
  }
  o.uv = ((int) (o.uv * 10.0 + 0.5) / 10.0); // Round to one decimal
  o.Dv = (o.uv == 0.0) ? 0 : ((int) (o.Dv + 0.5)); // Round to integer
  return o;
}

void loop()
{
  readIndex++;
  if (readIndex >= num1mReadings) {
    readIndex = 0;
  }

  /* 
   * Wind speed reading 
   */
  sensorValue = analogRead(ANEMOMETER_ANALOG_PIN); //Get a value between 0 and 1023 from the analog pin connected to the anemometer
  sensorValue = (sensorValue < wsMin) ? wsMin : sensorValue;
  windSpeed = (float)(sensorValue - wsMin)*windSpeedMax/(wsMax - wsMin);
  windSpeedReadings[readIndex] = windSpeed;

  Sprint(F("Reading: "));
  Sprint(readIndex);
  Sprint(F(", Wind speed sensor value: "));
  Sprint(sensorValue);
  Sprint(F(", wind speed: "));
  Sprint(windSpeed);
  Sprint(F(" m/s."));

  /* 
   * Wind vane reading 
   */
  const float dirTable[] PROGMEM = {0.0, 22.5, 45.0, 67.5, 90.0, 112.5, 135.0, 157.5, 180.0, 202.5, 225.0, 247.5, 270.0, 292.5, 315.0, 337.5};
  sensorValue = (windSpeed > 0) ? analogRead(WIND_VANE_ANALOG_PIN) : wdMin; //Get a value between 0 and 1023 from the analog pin connected to the wind vane
  sensorValue = (sensorValue < wdMin) ? wdMin : sensorValue;

  windDir = (sensorValue - wdMin)*337.5/(wdMax - wdMin); // This will be close but not exact.
  // Find the closest of the 16 predefined wind directions
  for (int i = 0; i < 16; ++i)
  {
    if (windDir < (dirTable[i] + 11.25)) {
      windDir = dirTable[i];
      break;
    }
  }
  windDirReadings[readIndex] = windDir;

  Sprint(F("\tWind direction sensor value: "));
  Sprint(sensorValue);
  Sprint(F(", wind direction: "));
  Sprint(windDir);
  Sprintln(F("°"));

  if (readIndex == num1mReadings - 1) {
    minute2Index++;
    minute2Index = (minute2Index >= num2mReadings) ? 0 : minute2Index;
    minute10Index++;
    minute10Index = (minute10Index >= num10mReadings) ? 0 : minute10Index;
    got2mins = (minute2Index == num2mReadings-1) ? true : got2mins; // One time switch
    got10mins = (minute10Index == num10mReadings-1) ? true : got10mins;

    cycleCountWindSpeed++;
    cycleCountWindGust++;
    cycleCountWindGustDir++;
    cycleCountWindDir++;
    cycleCountWindSpeed2m++;
    cycleCountWindGust2m++;
    cycleCountWindGustDir2m++;
    cycleCountWindDir2m++;
    cycleCountWindSpeed10m++;
    cycleCountWindGust10m++;
    cycleCountWindGustDir10m++;
    cycleCountWindDir10m++;

    struct speedAndDir o;
    o = windvec(windSpeedReadings, windDirReadings, num1mReadings);
    Sprint(F("\nWind vector calculation results: Speed: "));
    Sprint(o.uv);
    Sprint(F(" m/s"));
    Sprint(F(" \tDirection: "));
    Sprint(o.Dv);
    Sprintln(F("°\n"));

    float gust = 0;
    uint16_t gustDir = 0;
    for (int i = 0; i < num1mReadings; ++i)
    {
      if (windSpeedReadings[i] > gust)
        gust = windSpeedReadings[i];
        gustDir = windDirReadings[i];
    }
    gust = ((int) (gust * 10.0 + 0.5) / 10.0);

    windSpeedReadings10m[minute10Index] = windSpeedReadings2m[minute2Index] = o.uv;
    windDirReadings10m[minute10Index] = windDirReadings2m[minute2Index] = o.Dv;
    windGustReadings10m[minute10Index] = windGustReadings2m[minute2Index] = gust;
    windGustDirReadings10m[minute10Index] = windGustDirReadings2m[minute2Index] = gustDir;

    if ((o.uv != last_wspeed) or (cycleCountWindSpeed >= FORCE_TRANSMIT_CYCLE)) {
      cycleCountWindSpeed = 0;
      last_wspeed = o.uv;
      Sprint(F("Sending wind speed: "));
      Sprint(o.uv);
      Sprintln(F(" m/s"));
      send(msgWSpeed.set(o.uv, 1));
      wait(DWELL_TIME);
    }
    if ((gust != last_wgust) or (cycleCountWindGust >= FORCE_TRANSMIT_CYCLE)) {
      cycleCountWindGust = 0;
      last_wgust = gust;
      Sprint(F("Sending wind gust speed: "));
      Sprint(gust);
      Sprintln(F(" m/s"));
      send(msgWGust.set(gust, 1));
      wait(DWELL_TIME);
    }
    if ((o.Dv != last_wdirection) or (cycleCountWindDir >= FORCE_TRANSMIT_CYCLE)) {
      cycleCountWindDir = 0;
      last_wdirection = o.Dv;
      Sprint(F("Sending wind direction: "));
      Sprint(o.Dv);
      Sprintln(F("°"));
      send(msgWDirection.set(o.Dv, 0));
      wait(DWELL_TIME);
    }
    if ((gustDir != last_wgustdirection) or (cycleCountWindGustDir >= FORCE_TRANSMIT_CYCLE)) {
      cycleCountWindGustDir = 0;
      last_wgustdirection = gustDir;
      Sprint(F("Sending wind gust direction: "));
      Sprint(gustDir);
      Sprintln(F("°"));
      send(msgWGustDir.set(gustDir, 0));
      wait(DWELL_TIME);
    }
    // Do the 2 minute average but only if we have been running for 2 minutes or more.
    if (got2mins) {
      o = windvec(windSpeedReadings2m, windDirReadings2m, num2mReadings);
      Sprint(F("\n==========2 minute wind vector calculation results: Speed: "));
      Sprint(o.uv);
      Sprint(F(" m/s"));
      Sprint(F(" \tDirection: "));
      Sprint(o.Dv);
      Sprintln(F("°\n"));

      gust = gustDir = 0;
      for (int i = 0; i < num2mReadings; ++i)
      {
        if (windGustReadings2m[i] > gust)
          gust = windGustReadings2m[i];
          gustDir = windDirReadings2m[i];
      }
      gust = ((int) (gust * 10.0 + 0.5) / 10.0);

      if ((o.uv != last_wspeed2m) or (cycleCountWindSpeed2m >= FORCE_TRANSMIT_CYCLE)) {
        cycleCountWindSpeed2m = 0;
        last_wspeed2m = o.uv;
        Sprint(F("Sending 2 min wind speed: "));
        Sprint(o.uv);
        Sprintln(F(" m/s"));
        send(msgWSpeed2m.set(o.uv, 1));
        wait(DWELL_TIME);
      }
      if ((gust != last_wgust2m) or (cycleCountWindGust2m >= FORCE_TRANSMIT_CYCLE)) {
        cycleCountWindGust2m = 0;
        last_wgust2m = gust;
        Sprint(F("Sending 2 min wind gust speed: "));
        Sprint(gust);
        Sprintln(F(" m/s"));
        send(msgWGust2m.set(gust, 1));
        wait(DWELL_TIME);
      }
      if ((o.Dv != last_wdirection2m) or (cycleCountWindDir2m >= FORCE_TRANSMIT_CYCLE)) {
        cycleCountWindDir2m = 0;
        last_wdirection2m = o.Dv;
        Sprint(F("Sending 2 min wind direction: "));
        Sprint(o.Dv);
        Sprintln(F("°"));
        send(msgWDirection2m.set(o.Dv, 0));
        wait(DWELL_TIME);
      }
      if ((gustDir != last_wgustdirection2m) or (cycleCountWindGustDir2m >= FORCE_TRANSMIT_CYCLE)) {
        cycleCountWindGustDir2m = 0;
        last_wgustdirection2m = gustDir;
        Sprint(F("Sending 2 min wind gust direction: "));
        Sprint(gustDir);
        Sprintln(F("°"));
        send(msgWGust2mDir.set(gustDir, 0));
        wait(DWELL_TIME);
      }
    }

    // Do the 10 minute average but only if we have been running for 10 minutes or more.
    if (got10mins) {
      o = windvec(windSpeedReadings10m, windDirReadings10m, num10mReadings);
      Sprint(F("\n#############10 minute wind vector calculation results: Speed: "));
      Sprint(o.uv);
      Sprint(F(" m/s"));
      Sprint(F(" \tDirection: "));
      Sprint(o.Dv);
      Sprintln(F("°\n"));

      gust = gustDir = 0;
      for (int i = 0; i < num10mReadings; ++i)
      {
        if (windGustReadings10m[i] > gust)
          gust = windGustReadings10m[i];
          gustDir = windDirReadings10m[i];
      }
      gust = ((int) (gust * 10.0 + 0.5) / 10.0);

      if ((o.uv != last_wspeed10m) or (cycleCountWindSpeed10m >= FORCE_TRANSMIT_CYCLE)) {
        cycleCountWindSpeed10m = 0;
        last_wspeed10m = o.uv;
        Sprint(F("Sending 10 min wind speed: "));
        Sprint(o.uv);
        Sprintln(F(" m/s"));
        send(msgWSpeed10m.set(o.uv, 1));
        wait(DWELL_TIME);
      }
      if ((gust != last_wgust10m) or (cycleCountWindGust10m >= FORCE_TRANSMIT_CYCLE)) {
        cycleCountWindGust10m = 0;
        last_wgust10m = gust;
        Sprint(F("Sending 10 min wind gust speed: "));
        Sprint(gust);
        Sprintln(F(" m/s"));
        send(msgWGust10m.set(gust, 1));
        wait(DWELL_TIME);
      }
      if ((o.Dv != last_wdirection10m) or (cycleCountWindDir10m >= FORCE_TRANSMIT_CYCLE)) {
        cycleCountWindDir10m = 0;
        last_wdirection10m = o.Dv;
        Sprint(F("Sending 10 min wind direction: "));
        Sprint(o.Dv);
        Sprintln(F("°"));
        send(msgWDirection10m.set(o.Dv, 0));
        wait(DWELL_TIME);
      }
      if ((gustDir != last_wgustdirection10m) or (cycleCountWindGustDir10m >= FORCE_TRANSMIT_CYCLE)) {
        cycleCountWindGustDir10m = 0;
        last_wgustdirection10m = gustDir;
        Sprint(F("Sending 10 min wind gust direction: "));
        Sprint(gustDir);
        Sprintln(F("°"));
        send(msgWGust10mDir.set(gustDir, 0));
        wait(DWELL_TIME);
      }
    }
  }
  
  wait(WAIT_TIME);
}

Feel free to improve the code if you want. It's occupying a great deal of dynamic memory. I guess that the wind directions could be stored in a uint16_t type instead (multiplied by 10) but I haven't done that.

The arrangement above is temporary. I just used what I had available.

How would you guys protect one of these capacitive soil moisture sensors from moisture in case the probe shall be buried 20 cm deep in the soil outdoors.

The way they are made now, they may only be used in a indoor flower pot and even then there is a risk that the probes electronic components will be drowned in water while watering your flowers. Ideally, they should be water proof from the beginning, that's what I think.

Anyway, now I have a few of them and I intend to do a solar powered a multi depth soil moisture sensor using capacitive soil moisture sensors at various depths.

So, how to protect them?

I have an idea but I'm not sure it's working: Put it partly inside a plastic tube and cover the electronics with 2 component expoxy glue. ...

EDIT 1 : maybe silicone rubber would work...
EDIT 2 : Adding a photo of an untested prototype. Plastic housing filled with construction silicone rubber!

EDIT 3: Prototype sensor works great. (At least for the moment. I hope it will last several years.)
Cheers!

Sorry for the monologue!

Today I found a seller on E-bay that has most of the things that I will need. The new strategy is to buy many items from a single seller in a single transaction. Kindly asking him to put everything inside one box (We'll see if GONG TAO manages to do that)

The sellers store: https://www.ebay.com/str/modulefans

There are many other stores too of course but I think the above mentioned is quite good.

Cheers!

Hello @sundberg84

What if feeding a Pro Mini 3.3V (EasyPCB Nrf24l01+ edition rev 10) with regulated power on RAW. (I have 5 VDC). I guess I can feed the radio via the VCC terminal instead of using an external voltage regulator. Can the EasyPCB be used in such a setup?

Edit: To answer my own question. I should RTFM

It states clearly that:

"(If you are using regulated 3.3v, use 5v instructions but skip the voltage regulator and bypass this with a jumper between Vin and Vout"

Thanks anyway!

@hek

I let 1126-202 grams water slowly flow into the 55 cm2 gauge and it generated 475 tips.

That gives me 0.3537 mm/tip. I'll go with that.

My problem was caused by the fact that the radio was inserted into a socket. The 4.7uF stabilizing capacitor was put on the main board side of the socket. Moving the capacitor to the radio board or just soldering the radio to the main board (without using a socket) solved the problem. So, don't use a socket between the radio and the stabilizing capacitor.

Another interesting thing is that by putting a finger onto the antenna also solved the problem. I could use that method for testing all my radios (using the socket) before permanently soldering them onto the main board.

@hek said:

It takes a few failed transmission before it tries to "find new parent". Not sure what happended here without seeing the node log.

@mfalkvidd said:

@รอเรือ which version are you using? 2.0 has a problem with nodes that go back to sleep too soon after a failed send. This is fixed in the development version. See https://github.com/mysensors/MySensors/pull/558 for details.

Thanks guys! Well, I'm on 2.0.0. I'm not the "adventurous type" so I'm not on the development version if You get my point (ha ha).

It's good to know that there exists some healing mechanisms in the communication. I might wait for the next stable release or I might build me a dedicated "MySensor : RepeaterNode" with an external antenna to facilitate the communication with my upcoming battery powered nodes in my garden and for the lawn mower that really must be automated soon.

Hej tjolahopp! (Cheers!)

I'm currently in the process of trying to figure out why one of my battery powered nodes isn't working very well with a newly purchased NRF24L01+PA+LNA module. I've shielded it as described in earlier posts. There is plenty of pure power in the batteries.

Just as in the case for @pkjjneal it works well only if I'm touching the antenna with a finger.

I decided to look inside the antenna:

As you see above, it starts with an antenna cable that leads to a half wave dipole (where the antenna element is of about 1/4 wave length) and there is a "sleeve balun" going back over the cable . I can find no ground plane though. The problem that I can see is that the antenna length is 27 mm where it should optimally be 28.8 mm.

Now, if I remove the antenna completely my node works quite well. At least better than if I use the original antenna unmodified.

If I insert a wire (DIY antenna made by a paper clip) extending 121 mm out of the antenna sockets forming a full wave length antenna things work great.

I also modified the original antenna so that the antenna element becomes 28.8 mm. It works a bit better but it's far from perfect and communication errors are shown in the log.

As the final test, I added a nice ground plane to the original antenna and now it works really perfect!

So what can I learn from this?

My test rig is an EasyPCB powered with batteries. I'm quite sure that my NRF24L01+PA+LNA module used in another scenario, for example connected to a Arduino Nano fed by a FTDI connector could actually work. It's because it would create a different environment. The antenna will work in relation to what it's connected to, shielding the grounding, and surrounding objects. Capacitive and inductive reactances are involved in mysterious ways.

Anyway. My conclusion is that the two original antennas I have are not working very good. They obviously have the wrong length just a little bit, and I'd say that the the way the antenna is constructed with the sleeve balun and no ground plane, doesn't seem to work well. At least not here.

I'll do some more experimenting with making my own antennas. Starting with taking apart an original antenna is not so bad, I can solder anything (solderable) onto the cable.

Cheers!

From wikipedia:

Sleeve balun
At VHF frequencies, a sleeve balun can also be built to remove feeder radiation.

Another narrow-band design is to use a λ/4 length of metal pipe. The coaxial cable is placed inside the pipe; at one end the braid is wired to the pipe while at the other end no connection is made to the pipe. The balanced end of this balun is at the end where no connection is made to the pipe. The λ/4 conductor acts as a transformer, converting the zero impedance at the short to the braid into an infinite impedance at the open end. This infinite impedance at the open end of the pipe prevents current flowing into the outer coax formed by the outside of the inner coax shield and the pipe, forcing the current to remain in the inside coax.

Thanks @Mathea90 for bringing up this interesting subject.

It's sure difficult I believe to find a power supply for various Arduino projects that's both reliable and has a low cost.

@sundberg84 made a nice breakout PCB for the HLK-PM01, that "was considered at that time (2015-2017) the best AC to DC 5v module option (within reasonable price range)."

I hesitate though to build them due to that they will not be certified and if I cause a fire at my home, my home insurance may not cover the damages that can arise. With that being said, I'm quite sure that the HLK-PM01-breakout-board is by far much more safer than many wall plug chargers marked with CE (China Export).

It would be nice to have a breakout board that can turn the power from any random 5V wall plug charger into something that's clean and ripple free with a good margin to feed NRF24L01+ nodes with. With such a board I wouldn't have to be involved in working directly with 230V AC.

Meanwhile I'll probably try to build me a couple of LC filters using prototype breadboards.

Thanks again and keep up the good work!

@yveaux said in CDEBYTE's new NRF24 modules are great! (and cheap):

This patch makes both regular and amplified nRF24 modules work correctly!

Dear @Yveaux

Thanks for all the work you've put into investigating this issue.

I have a different brand of the Nano IO Shield but the quality is equally very low. I guess I'll need to inspect them carefully before I use them. I guess I have 10 of them and I will try to apply the HW patch you've suggested but I'm not sure I'll be able to make it, I don't have any SMD resistors and they are to small to work with for me. I'll need to give it a try anyway.

Thanks again and merry christmas btw

@Yveaux Thanks!

Nice graph. I will do something similar in Grafana. I think my MySensors device should also report every minute, perhaps using the highest sampled value. All values are sent to MQTT by my gateway and my Home Automation will store the time value pairs in influxdb. Right now I'm waiting for the hardware to arrive...

Hello all!

I'm building a PM2.5 particle matter sensor and I'm trying to figure out how I would go about to detect sudden changes of measured particles occurs.

I expect that there is a background level of particle matters that vary very slowly maybe between 0 and 20 µg/m3. I'd want to be alerted if that level rises all off a sudden. That happens frequently here when the flue gases from my neighbors chimney flows towards the ground level and enters my mechanical ventilation intake. I'd like the alert to be active until "normal" levels have been reached and a new alert if it happens again after that.

I'm putting my question here in hope that you might happen to know a "software design pattern" some reusable solution for a similar problem. I have seen a Lua Script for Humidity control that does a similar thing but a c++ code snippet to be inspired by would make things easier.

Do you have any idea about how this should be done clean and beautifully?

Thanks in advance. Cheers!

@mfalkvidd Thanks a lot!

I just made some tests and it looks promising.

Hello there!

My MAX7219 LED dot matrix display is working great using hardware SPI using pin 11 for MOSI and pin 13 for SCK on a Arduino NANO.
Now, I'd like to use a nRF24L01+ radio as well which also claims using the same ports 11 and 13 for MOSI and SCK.

MAX7219 can use software SPI instead so that I can use any digital pins of the Arduino. The problem is that when using software SPI it turns out to be slower and it doesn't look well on my double height display (2x8 matrixes). The upper part of the double height display lags. Therefore I'd like to use pin 11 and pin 13 for the MAX7219 LED dot matrix display but AFAIK the radio must use the same pins.

Any ideas how that can be solved?!

@rmh said in EV Charger (type 2) with RESTful API and Wifi recommendations?:

@รอเร-อ btw Normal single phase type 2 charging on an EV is 32a = 7 Kw. If your ev can charge at 22Kw, then it will need a 3 phase supply. OpenEVSE can do this but you will need to put a 3 phase contactor in it.
R

Thanks a lot. That seems to be exactly what I'm looking for. I didn't order the kit though. I ordered the EmonEVSE WiFi Connected EV Charging Station IEC 60947-5 (Type-2)

I'm very excited to get started. Ohh... I'll need an EV too... ha ha

Hi there!

Time for me to invest in a EV Charger (type 2).

Of course I'd like it to have a RESTful API and Wifi. Even better if it could connect to my MQTT server as well. 22 kW would be fine.

I can't just install any "smart" charger that measures the used grid power because it can't determine the direction of the current. I export solar energy daytime which makes power flow outwards to the grid. I'd like to be able to set the max power depending on how much solar power I produce and how much I can import. If I can control when charging occurs I can also select the cheapest hours.

BTW, I prefer to buy my EV charger in Europe.

Cheers!

@yveaux

I've managed to replace the SMD resistors according to your suggested hack described above. It wasn't easy though. Anyway, it seems to work well. Thanks!!!

@yveaux said in CDEBYTE's new NRF24 modules are great! (and cheap):

This patch makes both regular and amplified nRF24 modules work correctly!

Dear @Yveaux

Thanks for all the work you've put into investigating this issue.

I have a different brand of the Nano IO Shield but the quality is equally very low. I guess I'll need to inspect them carefully before I use them. I guess I have 10 of them and I will try to apply the HW patch you've suggested but I'm not sure I'll be able to make it, I don't have any SMD resistors and they are to small to work with for me. I'll need to give it a try anyway.

Thanks again and merry christmas btw

@skywatch said in CDEBYTE's new NRF24 modules are great! (and cheap):

What current rating is the power source you are using?

I intend to run them on power level RF24_PA_MAX. I have tried other power levels in my efforts without any success.

@yveaux said in CDEBYTE's new NRF24 modules are great! (and cheap):

recently received the same Nano IO shields and discovered the IO lines to the nRF are fed through a voltage divider; levels are halved w.r.t. direct connection.
According to Nordic's datasheet this should be ok (minimum HIGH level input voltage is 0.7 * VDD, so 0.7 * 3.3V = 2.31V) as long as your Arduino is fed with 5V this should just work, but it is tricky IMHO.
You could measure the VCC of the Nano to see if it is below 5V, or try powering the board through the power jack and see if things improve.

That's interesting. I'm powering it with USB only but i have tried to connect an additional power source as well but it made no difference, I will do some more tests and measure the voltage levels.

@yveaux said in CDEBYTE's new NRF24 modules are great! (and cheap):

Did you also try the shielded module with #define MY_RF24_PA_LEVEL RF24_PA_MIN ?

From what I recall, I have tried RF24_PA_LOW. I will test RF24_PA_MIN too.

@yveaux said in CDEBYTE's new NRF24 modules are great! (and cheap):

Currently I'm out of Nanos, but as soon as the new batch comes in I can replicate your setup.

I'd be happy to send you one from my batch. Please send me a PM if you'd like that.

@alowhum said in CDEBYTE's new NRF24 modules are great! (and cheap):

Since moving to these boards all my connection troubles have stopped. I'm very happy with them.

Sounds very promising

@yveaux

I have spent 2 days trying to solve my various NRF24 related problems at my home.

What I'd like to achieve is to make my serial gateway using a NRF24-transciever with an external antenna to extends it's range.

CDEBYTE's new NRF24-transciever (the unshielded one) works in my serial gateway (built with a Nano IO Shield) and fed with USB power only. I can attach a separate power source if I want to but it seems to work well without it.

However, CDEBYTE's new shielded NRF24-transciever (Shielded nRF24L01 PA+LNA) refuses to work. I get only NACKs in the log even if I attach a separate power source. I've also tried just connecting my Nano board directly to the radio with cables (without the IO shield) just like in the Build a serial gateway demo. (I've tried all kind of power settings) I also tried to power the radio with a battery. Those NACKs are resilient indeed. Of course I've tried all kind of decouple capacitors and several combinations of electrolytic and ceramic ones... No way.

BUT, there is always a but isn't there? ... I have managed to get the CDEBYTE Shielded nRF24L01 PA+LNA to work stable on a battery powered node, a Pro Mini ATmega 328 (1.8V 1 MHz). I can't tell why that works while not working with the Nano.

My current working solution is using the "old" unshielded nRF24L01 PA+LNA mounted on the Nano IO Shield fed with usb power only. #define MY_RF24_PA_LEVEL RF24_PA_MAX While this seems to work (at least for the moment) I can not just switch to using the shielded radio.

So if someone succeeds using the CDEBYTE Shielded nRF24L01 PA+LNA connected to a Nano board I'm interested to hear how you made it work.

The thing is that everything that I have tried gives so random results that it's driving me crazy. Whatever seems to work one minute stops to work the next minute.